The invention is in the field of measurement gauge that is used to assist in accurately placing the braces (individual attachments primarily composed of brackets and tubes) onto the upper and lower teeth on an orthodontic patient.
Presently, all measurement gauges used to position attachments on teeth function by making a linear measurement from the edges or cusp tips of all anterior (front) or posterior (back) teeth on the labial (lip) or buccal (cheek) side of the individual teeth toward the gingival (gum). This measurement is at a set distance from these landmarks i.e. cusp tips and biting edges of all teeth. Due to the anatomic variation in the height of cusps of posterior teeth, random wear patterns, and occasional cusp fractures, this method has numerous shortcomings in accuracy.
In reality, the orthodontist wants to position the attachments on all teeth so that the marginal ridges of the posterior teeth (the biting surface peripheral ridges located on the interproximal or side of the tooth) line up next to adjacent teeth in height. The marginal ridges should line up with little or no individual tooth marginal ridge variation in height to achieve the correct position of both upper and lower posterior teeth in order to allow opposing teeth to fit together when a person bites (or occludes) their teeth together.
The attachments on the posterior teeth should initially be positioned on each tooth so that when a straight wire (bent in the shape of an upper or lower dental arch of teeth) is engaged in the brackets and tubes, the teeth being adjusted will eventually be ideally aligned one to the other in either an upper or lower dental arch, and when the opposing teeth are brought together in a neutral bite, they occlude (fit together) ideally.
There accordingly remains a need for an accurate and easy to use gauge for measuring and/or marking teeth of an orthodontic patient for placement of braces thereon.
The invention provides a gauge that ideally accomplishes the need to measure and/or mark teeth easily and accurately so that braces can be correctly placed on the teeth in the ideal occluso-gingival position.
The invention provides a gauge with two arms. The first arm has two measuring axes. The first axis, (axis A) extends longitudinally along the long axis of the first arm and is used to measure the anterior teeth, i.e. the upper or lower cuspids and incisors. A vertical extension 38 is attached at a right angle to axis A and lies along an axis B, and the vertical extension 38 is typically rested on the mesial (the one closest to the front of the mouth) marginal ridge of a posterior tooth with axis A perpendicular to axis B and held parallel to the long axis of the tooth. The second arm of the gauge carries a pointed element, which may include an assortment of marking means, including but not limited to a pencil lead, washable inks delivered through a fine point, a grease pencil marker, or other known marking means or a non-marking means. The key element or measurement of the difference between axis A and the vertical tip of the axis B is approximately 2.5 mm with a variation of about 0.50 mm for most patients.